"Attics Of My Life" by Larry Campbell and Teresa Williams, with Amy Helm on the third part of the delicious 3-part harmony singing. The song was written by Jerry Garcia and Robert Hunter, and if it was recorded by The Dead I doubt it sounds as good as this version. Jerry wrote some good songs, but he and Bob’s harmonies were rather sour sounding (calm down Deadheads, you know it’s true). The 3-part by Larry, Teresa, and Amy is Angelic.
By the way, Garcia was himself a fan of The Louvin Brothers, and Hillbilly and Bluegrass music in general. Most of his side-projects were in those genres of music, beginning with Old & In The Way.